If you name the Excel range before establishing the link via copy/paste, the link will refer to the named range and will expand/contract to reflect changes in the named range's scope.

Even now, provided the linked table has been inserted as in-line with text, if you name the Excel range and edit the LINK field code in Word, the same result can be achieved. To do the latter, select the linked table and press Shift-F9 to expose the field code, which will look something like:
{LINK Excel.Sheet.8 "C:\\Users\\PWindsor\\Documents\\Path\\Excel Table.xls" "Sheet1!R1C1:R10C10" \a \p}
Simply replace 'Sheet1!R1C1:R10C10' with the named range, then press F9 to refresh the link.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]